At a loss for things to do this woozy post-Christmas weekend? Well, if you have access to a garage or basement — or even just some extra room on your dining table — you could always take up a hobby that is exploding in popularity across the Atlantic: genetic engineering. Or, to use the more fashionable term, “biohacking”.

Anecdotal evidence suggests that thousands of Americans now spend their free time consulting the internet, jerry-rigging laboratory equipment, and tinkering with the very foundations of life on Earth as we know it.

“People can really work on projects for the good of humanity while learning about something they want to learn about in the process,“ says Meredith Patterson, 31, a computer programmer by day turned biohacker by night.

In her San Francisco dining room Ms Patterson is currently attempting to rewire the DNA of yoghurt bacteria so that they will glow green to signal the presence of melamine, the chemical that infamously turned Chinese-made baby milk formula into poison.

Ms Patterson says that she picked up the basics of genetic engineering from scientific papers and Google.

All she needed for her project was a jar of yoghurt, some jellyfish DNA — purchased online for less than $100 (£65) from a biological supply company — and a few pieces of lab equipment (including a DNA analyser), which she constructed herself for less than $25. Eventually, say experts, such equipment could be sold in kits: a kind of My Little Genetically-Altered Lifeform playset for adults.

While acknowledging the potential risk of unleashing a genetically altered Frankenstein's monster on the public, biohackers argue that it was DIYers who brought about America's other great technological revolution: that of the personal computer.

Indeed, Apple and Google were created in hobbyists' garages, and have since gone on to change millions of lives for the better while contributing billions of dollars to the global economy.

Regardless, the growth in popularity of biohacking seems unstoppable. In Cambridge, Massachusetts, an organisation named DIYbio is busy setting up a community lab where people can use specialist equipment such as a freezer capable of storing bacteria at ninus 62C.

The group's co-founder, Mackenzie Cowell, 24, who studied biology at university, predicts that some biohackers are likely to make breakthroughs in everything from vaccines to super-efficient fuels. Others will simply fool around, he says: for example, using squid genes to make tattoos glow in the dark.

All of which he believes will ultimately benefit humanity. “We should try to make science more sexy and more fun and more like a game,” he says.

Alas, not everyone agrees. Jim Thomas, of ETC Group, a biotechnology watchdog group, says that synthetic organisms could ultimately escape and cause outbreaks of incurable diseases or unpredictable environmental damage. “Once you move to people working in their garage or other informal locations, there's no safety processes in place,” he says, adding that terrorists could be inspired by amateur genetic tinkering to launch a devastating bioattack on America.

Mrs Patterson shrugs at such arguments, however. “A terrorist doesn't need to go to the DIYbio community,” she says. “They can just enrol in their local college.”